1. Field of the Invention
The present invention relates to a automatic tool changer capable of automatically replacing a tool used in a machine tool.
2. Description of the Related Art
Conventionally, automatic tool changers that automatically replace tools mounted on a spindle of machine tools have been used. Such a automatic tool changers apparatus has a plurality of tools necessary for work preset thereto and is configured to automatically replace a tool mounted on the spindle of the machine tool with a tool specified in accordance with the processing state by performing a turning operation of a tool magazine to index the tool and attaching/detaching the tool to/from the spindle.
FIGS. 4 and 5 are views showing a conventional automatic tool changer and a tool magazine is made rotationally movable in a direction allowing the tool magazine to approach/separate from a spindle head.
In such a automatic tool changer, the whole tool magazine can be moved from the neighborhood of the spindle head during processing and thus, a processing area can be made wider. In addition, the spindle head can be made larger than when the tool magazine is not movable and thus, the stiffness of the spindle can be increased.
JP 63-062630 A discloses a automatic tool changer of a machine tool in a mode in which a spindle motor is used to drive the tool magazine to turn, wherein the processing area is secured widely by making the tool magazine rotationally movable in a direction allowing the tool magazine to approach/separate from the spindle head.
Some automatic tool changers have been enabled to secure a processing area widely or to increase the stiffness of the spindle by making the tool magazine rotationally movable in a direction allowing the tool magazine to approach/separate from the spindle head.
However, according to the above conventional technology and the automatic tool changer of a machine tool disclosed in JP 63-062630 A, the position of a magazine driving motor changes with the movement of a shaft of the machine tool and thus, the tool magazine can perform a turning operation only when the tool magazine is in a position approaching the spindle head as a tool replacement position and also the shaft of the machine tool is in a predetermined position.